Various manually driven carrier vehicles, for example, hand trucks and carts, are commonly used for moving objects that are otherwise inconvenient for a person to carry due to their number, size, and/or weight. Often, these vehicles have foldable chassis for ease of storage and transportation when not in use. These carriers typically have a frame with telescoping or folding handle and chassis comprising folding platform and wheels mounted on either a single axle or separate foldable arms. Chassis with wheels mounted on the single axle and some with the foldable arms have independently folding platform. However, chassis with interdepended folding of the platform and arms offer more compact option. The latter utilize either cam or gear mechanisms. Neither are lockable by themselves and require additional means and actions to prevent inadvertent folding. These means add complexity and expense to designing and manufacturing of the chassis and make handling of the carrier somewhat challenging for an average consumer.
Therefore, it is desirable to provide folding carrier chassis capable of being, at least, unfolded into a positively locked position by a single action. Additionally, it is desirable to have such carrier chassis be foldable relatively flat to provide for ease of storage and transportation.